Automotive vehicle bodies are typically constructed using stamped metal panels, which combine substantial overall strength and stiffness with a smooth, paintable exterior surface. With specific regard to vehicle hood panels (also referred to in the art as engine compartment hoods or bonnet structures), panel stiffness is often satisfied via the combination of a relatively high strength stamped metal outer or upper surface, referred to as an “A-surface”, coupled with a preformed inner or lower surface, referred to as a “B-surface”, supported by a series of engine-side or hat-section reinforcements. The hat-section reinforcements are typically positioned between the A- and B-surfaces of the hood, and include a pair of upper flanges oriented toward the A-surface as well as a single lower flange oriented toward the B-surface, with the upper and lower flanges interconnected by a web portion. This conventional hood construction increases the bending stiffness of the hood by placing relatively stiff material, usually stamped steel, as far away as possible from the neutral axis of bending of the hood.
In certain vehicle impact scenarios, an object may exert a downward force on the vehicle hood. Typically, vehicle hoods are deformable when a downward force is exerted thereto. However, the deformability of the hood and, correspondingly, the hood's ability to absorb energy may be impeded by the proximity of the hood to rigidly mounted components housed in the vehicle's engine (or forward) compartment. By way of example, the hood's ability to absorb energy through deformation can be significantly impeded where the hood and engine block are in close proximity. However, minimal clearance between the vehicle hood and the engine compartment components may provide significant benefits, such as improved driver visibility, increased aerodynamics, and more aesthetic appeal.
In contrast, additional clearance between the vehicle hood and engine compartment can increase the hood's ability to absorb energy when acted upon with a downward force. Therefore, notwithstanding other design concerns, it can also be advantageous to increase the clearance between the vehicle hood and the components housed in the engine compartment.